Housing

ABSTRACT

A housing is disclosed which may be used for a tachograph. The housing includes a battery holder and at least one fastening element arranged to fasten the battery holder to the housing. With the housing it is possible to mount a battery in an exchangeable manner while preventing the possibility of manipulating the components inside the housing during a changing of the battery. When the battery holder is mounted on the housing, the fastening element can only be accessed from the inside of the housing.

BACKGROUND OF THE INVENTION

The invention relates to a housing, in particular housing of atachograph, in particular of a tachograph of a commercial vehicle, witha battery holder for fixing on the housing by means of a batteryreceptacle designed as part of a basic body, with at least one fasteningmeans for fastening the battery holder on the housing, with, in thestate of the battery holder in which it is fitted with the housing, thefastening means being accessible exclusively from the interior of thehousing.

The main focus of the use of the housing according to the invention isin the region of tachographs or devices for recording the workingperiods and rest periods of drivers of commercial vehicles. In additionto this preferred use, other uses are also conceivable, in particularthose in which a high degree of security against manipulation isrequired. Owing to the high economic and legal significance of the datato be recorded in the case of tachographs, the recordings have to bereliably protected against manipulations. The safeguards relate both tothe recording of data and the transmission of data and also thetransmission and storage of the recorded data in the card memory.Relevant standards impose strict requirements on the safety standard tobe achieved by the measures. In order to secure the data and maintainthe operation if there are problems with an external power supply of thetachograph, an additional power supply of the tachograph by means of anintegrated battery is indispensable. After a relatively long operatingperiod of the device, in particular in the case of intensive use of thepower provided by the battery, the battery needs to be changed, sincethe unit no longer provides the required voltage. For this reason, thebattery which is integrated in the device or the components adjacent toit have to have arrangements which permit the battery to be changed. Aprevious solution of this technical problem makes provision for thebattery to be inserted into a battery holder which is fastened to thehousing wall by means of a screw in such a manner that the batteryreceptacle of the battery holder protrudes into the housing through anopening in the wall of the housing. The screw fastening the batteryholder to the housing is accessible from the outside, with the resultthat, during a changing of the battery, after release of the screw thebattery holder can be removed from the opening of the housing wall andthe interior of the housing is thus accessible. The accessibility of theinterior of the housing during the absence of a power supply concealsthe risk of unnoticed manipulations of the electronic componentssituated there. In this connection, the changing of the battery isalways a welcome pretext for changes to the device that are undertakenwith fraudulent intent. Even a seal or safety device fixed on thefastening means of the battery holder is not capable of changinganything in this regard, since the maintaining of the operation of thedevice justifies the breaking open of the seal.

Starting from the problems and disadvantages of the prior art, theinvention has set itself the object of arranging a battery in achangeable manner on a housing and at the same time of eliminating thepossibility of the components situated in the housing being manipulatedwithin the context of the battery being changed.

European patent application EP 0 774 736 A2 has already disclosed anarrangement of the type mentioned at the beginning, in which thefastening of the battery holder is extremely complicated andcost-intensive on account of the security against manipulation which isendeavored to be achieved. German laid-open specification DE 195 45 537A1 describes a tachograph which can likewise have a battery in order tobuffer the contents of the memory.

EP 1 006 767 A2 discloses an electronic component with a housing whichcompletely surrounds a control unit which, inter alia, comprises a baseand a battery holder. The base contains a battery-holder fastening parton which cutouts are provided. Connecting pins are formed on the batteryholder and, in the assembled state, engage in the cutouts of thebattery-holder fastening part. In order to change the battery, thecontrol unit with the battery holder embedded therein has to be removedfrom the housing.

Starting from the problems and disadvantages of the prior art, theinvention has set itself the object of arranging a battery in achangeable manner on a housing and at the same time of eliminating thepossibility of the components situated in the housing being manipulatedwithin the context of the battery being changed.

To achieve the object, a housing of the type mentioned at the beginningis proposed which has the features of claim 1. The subclaims showadvantageous developments of the invention.

SUMMARY OF THE INVENTION

To achieve the object, a housing of the type mentioned at the beginningis proposed which has the features of claim 1. The subclaims showadvantageous developments of the invention.

The advantages of the invention come fully to fruition if the housinghas a recess into which the battery holder is at least partiallyinserted. The exposure of a recess of this type within the context ofchanging the battery is prevented, since the battery holder cannot beremoved from the recess. Although the fastening means may also bedesigned, according to the invention, as a screw or rivet, it isextremely advantageous for the production and the installation if thefastening means is designed as a spring-mounted latching hook or snap-inhook. This enables a preassembled battery holder of the type accordingto the invention, which has preferably already been fitted with abattery beforehand, to be fixed on the housing according to theinvention in one action. A latching hook is understood, according to theinvention, to mean a flexible component which, like a leaf spring, has apreferred bending direction on account of the design of the crosssection. At one end, the latching hook is fastened to an adjacentcomponent or is connected fixably to the latter, preferably as a singlepiece

The advantages of the invention come fully to fruition if the housinghas a recess into which the battery holder is at least partiallyinserted. The exposure of a recess of this type within the context ofchanging the battery is prevented, since the battery holder cannot beremoved from the recess. Although the fastening means may also bedesigned, according to the invention, as a screw or rivet, it isextremely advantageous for the production and the installation if thefastening means is designed as a spring-mounted latching hook or snap-inhook. This enables a preassembled battery holder of the type accordingto the invention, which has preferably already been fitted with abattery beforehand, to be fixed on the housing according to theinvention in one action. A latching hook is understood, according to theinvention, to mean a flexible component which, like a leaf spring, has apreferred bending direction on account of the design of the crosssection. At one end, the latching hook is fastened to an adjacentcomponent or is connected fixably to the latter, preferably as a singlepiece.

In the region of the opposite end, the latching hook with a projectionwhich has an edge and preferably has a shape co-ordinated with a matingedge on the component to be coupled by means of the latching hook. Theprojection extends in the direction of the movement normal of the springdeflection of the latching hook. Along a running co-ordinate through thecenters of gravity of the cross-sectional surfaces under correct loadingwithin the context of the joining process, the latching hook has abending of constant sign in the functionally essential region. A snap-inhook is a special design of the latching hook which, in contrast to thelatching hook, is deformed with a reversal of the sign of the bendingunder correct loading within the context of the joining process. In thisconnection, the reversal results from at least one spatial change inorientation of the running co-ordinate of the centers of gravity of thecross-sectional surfaces by at least 90°. This spatial profile providesa greater spring deflection for the snap-in hook.

Furthermore, for example in the case of the basic body of the batteryholder being designed as a plastic injection-molded component, thespring-mounted fastening element or the latching hook can be designed asa single piece with said basic body, so that the number of components iscost-effectively reduced.

Various embodiments are conceivable and expedient for the design of thespring-mounted fastening means. The embodiment of a spring-mountedfastening means is particularly advantageous if it has a barb which, inthe fitted state of the battery holder, bears against a mating edge. Inthis connection, it is possible for the spring-mounted fastening meansto be part of the battery holder according to the invention or else partof the housing. Since housings of the generic type preferably consist ofmetal, the spring-mounted fastening element can expediently be designedas a tongue which is punched out on the housing and, in the fittedstate, bears against a corresponding counterbearing of the batteryholder. In addition, it is also conceivable for plastic parts to bemolded onto the housing as spring-mounted fastening elements.

Particularly expedient is the design of the battery holder with a basicbody which is provided with a bearing surface which is formed on thehousing according to the invention, optionally with the interconnectionof a seal, on the outer side of a wall of the housing, in a mannersurrounding the recess into which the battery holder is partiallyinserted. In the embodiment with latching hooks which extend into theinterior of the housing, the battery holder according to the inventionhere additionally has the advantage of no additional leakages arisingdue to the fastening component extending through the battery holder andthrough a wall of the housing into the interior of the housing.

Fastening means which are spring-mounted on the bearing surface orlatching hooks which are spring-mounted essentially parallel to thebearing surface can advantageously be provided and extend into theinterior of the housing. For an automatic latching of the battery holderaccording to the invention into the housing, it is also expedient if thearrangement of the fastening means with respect to a further fasteningmeans or a corresponding counterbearing with respect to the fasteningmeans on the bearing surface has an excess length in relation to therecess in the housing. This excess length expediently correspondsessentially to the spring deflection or the sum of the springdeflections of the fastening means or more than one fastening means, sothat the battery holder is secured fixably to the greatest possibleextent without play in the recess in the wall of the housing.

An advantageous development of the invention makes provision for thefastening means to be designed in the manner of a snap-in hook. In thiscase, the snap-in hook advantageously has a V-shaped shape and isdesigned as a bent leaf spring. The kink of the bent leaf spring, whichkink arises because of the V-shape, is expediently rounded in such amanner that a U-shape is produced, in particular if the snap-in hookconsists of plastic. A first limb of the V- or U-shaped leaf spring isexpediently fastened at one end to the bearing surface and a second limbwhich adjoins the other end of the first limb, at the end which liesopposite the end connected to the first limb and points in the directionof the bearing surface, is designed there in a spring-mounted manneressentially parallel to the bearing surface. By means of the elasticdeformability of the fastening means, the battery holder, in spite ofthe excess length, can be introduced into the opening of the housingaccording to the invention. When the bearing surface of the batteryholder bears against the wall of the housing, the fastening means whichset up the excess length spring elastically back into the startingposition, so that the battery holder is secured fixably on the wall ofthe housing with the fastening means bearing against the inner side ofsaid wall.

For maximum reliability and stability of the mounting of the battery,the battery receptacle is expediently designed as a battery housing withan opening through which a battery can be introduced into the batteryhousing. Excellent stability is achieved if, in the case of an oblong,preferably cylindrical battery, the battery housing is likewise ofcylindrical design and the opening is situated on an end wall of thecylindrical battery housing. A battery housing shape expedientlydesigned statically in such a manner withstands the high mechanicalstresses, in particular the severe vibrations during operation of atachograph in a commercial vehicle, in spite of the high mass of thebattery. The size of the opening of the battery housing, which openingis to be closed, as a possible point of weakness is minimized in afunctionally suitable manner.

The opening of the battery housing is to be closable by means of aclosure. According to the invention, provision is made for, in thefitted state of the battery holder on the housing, the opening of thebattery housing not to point into the interior of the housing but ratherto point outward from the housing. In this manner, the opening of thehousing within the context of the changing of the battery is reliablyavoided. So that a changing of the battery nevertheless takes placewithout a disproportionately great amount of effort, it is expedient if,in the fitted state of the battery holder on the housing, the closure ofthe opening is accessible from the outside with respect to the housingand can be opened from the outside. In addition, it is expedient if theclosure of the opening is fastened releasably in the closed position bymeans of a fastening. In particular, elastically deformable fasteningmeans, for example spring-mounted barbs or latching hooks, are suitablefor this purpose.

So that a changing of the battery is always comprehensible, it isexpedient if the fastening of the closure is secured by means of a sealor the closure is sealed in a closed position independently of thefastening. So that the arrangements for providing a seal also satisfythe requirements with regard to accessibility at the point of the seal,it is expedient if a formation is fixed on the closure and, in theclosed position, is arranged in a recess of the battery holder and issecured in this position by means of a seal. If appropriate, a recesswhich corresponds with a corresponding formation on the battery holdermay also be provided on the closure.

An arrangement is expedient, in which the basic body of the batteryholder is provided with a bearing surface for bearing against thehousing, on which bearing surface the fastening means is arranged, andthe battery receptacle and the closure are connected to the basic body.In this connection, the closure is advantageously fastened to the basicbody by means of a film hinge. The film hinge is particularly readilysuitable for the fastening of the closure, since it can firstly beproduced cost-effectively and secondly fully satisfies the requirementswith regard to the infrequent actuation of the closure.

The previously described design of the battery receptacle is suitable inparticular for the arrangement of at least two contacts, a first contactand a second contact, with at least one contact being of spring-mounteddesign. In addition, a battery which has at least two lines to which thebattery voltage is applied can also be arranged in the batteryreceptacle. In the case of the embodiment with spring-mounted fasteningmeans for the mechanical fastening of the battery holder in the housing,all that is required for the installation on a housing of a batteryholder according to the invention, which has already been preassembledwith a battery, is for the battery holder to be inserted into theopening of the wall of the housing and for the lines emerging from thebattery to subsequently be connected to the adjacent electriccomponents.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

A special exemplary embodiment of the invention is described in greaterdetail below with reference for clarification purposes to drawings, inwhich:

FIG. 1 shows a perspective illustration of a housing according to theinvention with a battery holder according to the invention from a rearperspective,

FIG. 2 shows a perspective illustration of a battery holder according tothe invention in an open position from a front perspective,

FIG. 3 shows a perspective illustration of a battery holder according tothe invention in an open position from a rear perspective,

FIG. 4 shows a perspective illustration of a battery holder according tothe invention from a front perspective in a closed position,

FIG. 5 shows a rear view of a perspectively illustrated battery holderin a closed state, and

FIG. 6 shows a perspective illustration of a battery holder according tothe invention mounted on a housing according to the invention from aperspective inside the housing.

DETAILED DESCRIPTION OF THE INVENTION

In the illustration of FIG. 1, a housing 1 is provided with thereference number 1. A battery holder 2 according to the invention isfitted on the housing 1. The battery holder 2 is inserted a recesssituated in a rear wall 12 in such a manner that part of the batteryholder 2 is situated in the interior of the housing and the remainingpart of the battery holder 2 protrudes on the rear hide of the housing 1in a manner such that it is accessible from the outside.

The battery holder 2 has a basic body 3 which has a base plate 31, thebase plate 31 being divided into a first section 38 covered by a closure25 and a second, second section 39 provided with a seal 28. The batteryholder 2 is designed as a single piece as a plastic injection-moldedcomponent. Part of the basic body 3 of the battery holder 2 is a batteryreceptacle 4 which is designed as a cylindrical battery housing 22. Theclosure 25 is fixed on the base plate 31 of the basic body 3 by means ofa film hinge 32. Fixed on the closure 25, which, in the closed position,closes an opening of the battery housing 22, is a first spring-mountedelement 40 which clamps a battery (not illustrated) of cylindrical shapein the axial direction in the battery housing 22. On the side lyingopposite the film hinge 32, a formation 29 is fixed on the closure 25,which formation corresponds with a recess 30 of the second section 29 ofthe base plate 31 in such a manner that, in the closed position of theclosure 25 of the battery holder 2, the formation 29 is arranged in therecess 30 and can be secured in this position by means of a seal 28(illustrated in FIG. 1). Fixed on the basic body 3, on the side lyingopposite the film hinge 32 of the opening, are two spring-mountedelements 41 with second barbs 33 which secure the closure 25 at a secondedge 35 of the closure 25 in the closed position of the battery holder2.

On the side facing the housing 1, the basic body 3 of the battery holder2 has a bearing surface 11. Latching hooks with barbs 9 which aredesigned as snap-in hooks 17 are arranged on this bearing surface 11.These fastening means 5 are designed in plastic as leaf springs and havea first limb which is connected fixably to the basic body 3. The snap-inhooks 17 are of V-shaped shape, with a second limb of the V-shaped shapebeing designed such that it is spring-mounted parallel to the bearingsurface 11 on the side lying opposite the attachment to the first limb.The spring deflection of the second limb corresponds in sum essentiallyto the excess length which the arrangement comprising the spring-mountedfastening means 5, 13 and further counterbearings 14 has in relation tothe recess arranged in the wall 12 of the housing 1. In this manner, theelastic fastening means 5 on the wall 12 latch in a spring-mountedmanner in the recess of the housing 1. After installation of the batteryholder 2 according to the invention, the elastic fastening means 5 aresituated in the interior of the housing 1, SO that the battery holder 2cannot be removed from the wall 12 without the housing 1 being opened.

The battery holder 2 has, adjacent to the battery housing 22, anaperture 44 through which lines (not illustrated) coming from a battery(not illustrated) are introduced into the interior of the housing.

1. A housing for a tachograph which is useable in a commercial vehicle,the housing comprising: a battery holder having a basic body and abattery receptacle as part of the basic body, the battery holder beingarranged to be fixed on the housing by at least one fastening means, thefastening means arranged to be accessible exclusively from the interiorof the housing, a recess arranged to accommodate at least part of thebattery holder, and a wall having an inner side facing an interior ofthe housing and an outer side, wherein a bearing surface of the basicbody bears at least partially on the outer side of the wall of thehousing, surrounding the recess, wherein the fastening means is aspring-mounted latching hook extending from the bearing surface into theinterior of the housing.
 2. The housing according to claim 1, furthercomprising a closure arranged to be fastened in a closed position bymeans of at least one spring-mounted second barb.
 3. The housingaccording to claim 1, wherein the battery receptacle has at least twocontacts and at least one contact is of spring-mounted design.
 4. Thehousing according to claim 1, wherein the latching hook has at least onebarb which is arranged, in a fitted state of the battery holder, to bearagainst a mating edge.
 5. The housing according to claim 1, wherein: thelatching hook is arranged so as to be spring-mounted essentiallyparallel to the bearing surface; at least one of a further fasteningmeans and formation is arranged to act as a counter bearing to thelatching hook; and the latching hook arranged with respect to the atleast one of a further fastening means and formation, on a bearingsurface of the battery holder, has an excess length in relation to therecess which corresponds essentially to a spring deflection of thelatching hook or a sum of spring deflections of the fastening means. 6.The housing according to claim 5, wherein: the latching hook is asnap-in hook arranged to extend into the interior of the housing as asnap-in hook which starts from the bearing surface, the latching hook isa leaf spring bent in a V-shaped manner having a first limb fastened atone end to the bearing surface, and a second limb arranged to adjoin theother end of the first limb, and the second limb bears, at the end whichlies opposite to an end connected to the first limb and points in adirection of the bearing surface and is spring-mounted essentiallyparallel to the bearing surface, against a region which is adjacent tothe recess, so that the hook effects a securing of the bearing surfaceof the battery holder on the housing.
 7. The housing according to claim6, wherein the basic body is made by plastic injection-molding.
 8. Thehousing according to claim 6, wherein the housing is metal.
 9. Thehousing according to claim 6, wherein the battery receptacle comprisesan opening to receive a battery.
 10. The housing according to claim 9,wherein the opening is closable by means of a closure.
 11. The housingaccording to claim 9, wherein the opening is situated on an end side ofthe battery receptacle.
 12. The housing according to claim 9, wherein,in a fitted state of the battery holder on the housing, the opening ofthe battery housing points outward from the housing.
 13. The housingaccording to claim 12, wherein, in a fitted state of the battery holderon the housing, the closure of the opening is accessible from outsidethe housing and is arranged to be opened from the outside.
 14. Thehousing according to claim 13, wherein the closure of the opening isarranged to be fastened releasably in a closed position by means of afastener.
 15. The housing according to claim 5, wherein the batteryholder is designed to be preassembled with a battery.
 16. The housingaccording to claim 14, wherein the fastener is secured by means of aseal.
 17. The housing according to claim 16, wherein a formation isfixed on the closure and, in a closed position, is arranged in a recessof the battery holder and is secured in this position by means of aseal.
 18. The housing according to claim 17, wherein the batteryreceptacle and the closure are connected to the basic body.
 19. Thehousing according to claim 18, wherein the closure is fastened by meansof a film hinge.